As an individual ages, small sensory losses such as a decreased ability to hear nuances of emotion in speech impair cognition are noticed immediately by the person experiencing them are unusual and usually a sign of a serious problem are sufficiently filled in by the brain

Whether or not a given study has the possibility of causing harm to participants:

Give an example of a situation in which an individual's pursuit of economic self-interest may not benefit but instead harm the rest of society

Dr. robbins wants to know if there are different opinions regarding the value of public school education between native americans who have at least one relative who attended indian boarding school and native americans who have no family experience with indian boarding school. dr. robbins contacts 35 native american participants in each group. he wants each group to include younger as well as older adults, and a mix of male and female participants. he asks each person to complete a survey about their attitudes toward public education. the design of this study is: